A NEW LINER.

Dominion, Volume 1, Issue 226, 17 June 1908, Page 7

A NEW LINER.

SUBMARINE SIGNALLING.' BY TELEGRAPH —PRESS ASSOCIATION—COFTBKHIT (Rec. June 16, 11.22"p.m.) London, June 16. Tho trial trip of the now Aberdeen liner Pericles from Cardiff to London was a great success. The submarine signalling apparatus was tested, and was found to work perfectly.' VALUE OF SUBMARINE SIGNALLING. Tho Naval Director of tho Commonwealth, Captain Creswell, in an interview on the subject of submarine signalling by sound, 6ays it has added another sense for emplovment in tho art of navigation. With the ordinary sound signalling, it was so. difficult to locate the sound that no absolute reliance could be placed upon it. With submarine signalling, tho conditions wore much more favourable. Sound could bo heard up to 14 or IS miles, and, in addition, the exact bearing and direction of the Sound could bo ascertained. In a report furnished by officers of tho Admiralty it was stated that it would be possiblo for ships fitted with signalling apparatus to navigate in fogs with as much certainty as in clear weather. Tho invention was based, firstly, on the fact that sound was transmitted through water nt tho "rate of 4000 feet per second, as against 1100 feet in the atmosphere. In addition, the distributing factors of water wore not nearly so great. The sounding bell had an enormous thickness of lip, and it gave a peculiarly high note. It was worked oithor by electricity, or comprossed air, or by the ordinary motion of tho waves. The receiver, however, was the ingenious part of the contrivanco. The great difficulty to be overcomo was the ordinary noise of the ship's machinery. One of the conditions required for the transmission of sound through water, and securing its record, was to have a tank in the ship/containing a liquid heavier than water. By knowing the direction of the ship's head, the direction of danger could be ascertained within a point or two. The American coast was boing fitted with these submarine sound transmitters, and on large passenger- liners tho receiving instruments were boing installed. Although Australia was not. a " thick weather" country, there wero many places on the coast where tho sounding bolls might be established with advantage.